exchange of a Tile

i made a purchase on the 1 March and the second 1 on the 19th March,after i saw the type of a tile i put i realized on the other section of my house i would like to go with the other tile which is Arena White and i would like to exchange it with Perfetto

i went to the store on 23 March 2021 to make a request to exchange the tiles and to buy extra 9 boxes but you staff gave such an attitude that i cant exchange since i only had 2 boxes and its the same as making a return which really puzzled me ,return and exchange are not the same even in the account treatment is not the same and to think as well i was adding more business to you books ,i felt humiliated and not appreciated as a new client to you business

my house now is in a mess because my tiler cannot complete the work since i want this style of a tile and i cant be allowed to exchange it with the other 1 ,and because of this pathetic dragonial rules you imposed to clients i couldn't even but extra boxes i wanted to but i felt like i shouldn't have done business with you at all .as per consumer Act you cannot deny me to make an exchange why is that ,i want this to be sorted urgently or give me money back